Your viewpoint is rather naive in the mechanical world. OK it's enough to assemble a coffee table, now try an engine with 2,000 parts. Without a manual how can you set bearing clearances? How do you know how much thrust clearance there should be? How do you know which way up a piston ring goes, or how much torque to apply to a head bolt?
Machines are extremely complex, and that's before you even touch electronics and hydraulics, both of which are highly complex systems. Simply moving large machine parts safely requires documented procedures, let alone order of assembly.
Machines are extremely complex, and that's before you even touch electronics and hydraulics, both of which are highly complex systems. Simply moving large machine parts safely requires documented procedures, let alone order of assembly.